[oe] fftw recipes

[Andreas Müller]

Hi,

is there a technical reason why we have multiple fftw recipes (fftw /
fftwl / fftwf)?

or

before I start: Any complaints/comments if I

* merge all fftw's into one recipe named fftw splitting in multiple
packages (fftw / fftwl / fftwf / fftwq?)
* replace virtual/fftw by fftw
* make oe-core's alsa-utils fftw PACKAGFCONFIG[fftw] depending in fftw

Feedback welcome

Andreas